Safety gear-wheel.



' F. L. MORSE.

SAFETY GEAR WHEEL. APPLICATION FILED IAN-3.1911.

Fig.2.

Patented Nov. 16, 1915.

FRANK L. MORSE, 0F ITHACA, NEW YORK, ASSIGNOR TO MORSE CHAIN COMPANY, OF ITHACA, NEW YORK, A CORPORATION OF NEW YORK.

SAFETY GEAR-WHEEL.

Specification of Letters Patent.

Patented Nov. 116, 19515.

To all whom it may concern: I

Be it known that I, FRANK L. MORSE, a citizen of the United States, residin at Ithaca, in the county of Tompkins and tate of New York, have invented new and useful Improvements in a Safety Gear-Wheel, of which the following is a specification.

This invention relates to gearing and more particularly to power transmission mechanism having a positive driving connection, such as directly engaging gear teeth or chain drives operating upon sprocket wheels, the object being to provide an improved safet connection between the gear teeth and sha and adapted to yield upon excessive stresses to permit a relative movement between these parts and thereby prevent a breakage of some more important and expensive piece of the machinery when, for any reason there is a sudden stoppage of the driven member.

In the accompanying drawing, Figure 1 is a side elevation, and Fig. 2, a part plan and part horizontal section of a gear wheel embodying one form of my improvement.

According to this construction, the sprockets or gear teeth, 3, are carried upon a rim, 4, mounted with the capacity of relative movement upon the body or hub, 5, of the wheel .which is adapted to be keyed upon a shaft. While the gear teeth are fully shown in Fig. 1, only at certain portions of the rim, it will be readily understood that they extend all the way around the circumference of the wheel.

For the safety connection which is adapted to yield or to-be severed by excessive strains produced by the sudden stoppage of the driven wheel or shaft, I prefer to employ one or more pins or bolts, 6, by which the rim is fastened to the hub or body portion of the wheel, the bolts being of the desired size and metal to afford a certain amount of resistance to shear which may be readily varied to suit different conditions by varying the number or size of shearin bolts used. At the point where the shearing bolts; or pins, 6, pass through the rim, 4, and the flange, 7, of the hub, I preferably insert die blocks, 8, and 9, of hardened steel, so that 5 when the gear is subjected to excessive stress,

the pins, 6, will be readily sheared off and the rim, 4, then revolve relative to the shaft or hubof the wheel, thus preventing the the rim when the safety pins or bolts have shearedofl' due to excessive stresses.

' It will now be seenthat Ihave provided a very simple and eflective construction which operates as a rigid or integral gear or sprocket wheel as long as thesame is not subjected to excessive strains which would be liable to break the gear teeth or other important parts of the driving mechanism, but

that when such strains occur, the safety connection, that is the shearing pins are readily sheared ofl", thereby permitting the rim to continue to revolve upon its lubricated bearing surface on the hub or body of the wheel, without injury to any of the important parts. The pins may then be readily removed and renewed at little expense, thus placing the gear again in condition for operation with little or no loss of time or injury to the mechanism.

What I claim as new and desire to secure by Letters Patent, is:

A safety gear wheel comprising a body portion having two radially extending flanges with a bearing surface between the same, a rim having a web portion rotatably mounted on said bearing surface between said fiangesand provided with a lubricant groove, shearing bolts passing through said web and one of said flanges, and hardened metal dieblocks inserted in said web and flange at the shearing point of the bolt.

In testimony whereof I have hereunto set my hand.

FRANK L. MORSE.

Witnesses ALFRED B. WRAY, T. M. MANLEY. 

